Authorities have yet to respond to the allegations of a crackdown, but many Zimbabweans believe Mnangagwa is falling back on the tactics of his predecessor Robert Mugabe by using intimidation to crush dissent.
Mr Mnangagwa flew to Moscow to meet Vladimir Putin earlier this week.
The Zimbabwe Human Rights NGO Forum says the Internet restriction is "unwarranted, unjustifiable in the circumstances and is a tool of repression meant to mask the massive human rights violations which the state was preparing to commit".
Government officials were not immediately available for comment on the blackout, which critics say is an attempt to prevent images of heavy-handedness in dealing with protesters from being broadcast around the world.
The UN human rights office on Friday urged Zimbabwe to stop the crackdown, noting reports of intimidating door-to-door searches by security forces. A nurse attends to a man with a broken spine.
The statement says children as young as 9 have been reportedly tortured as security forces break into private homes.
Keith Frymore has a torn lip.
Zimbabwe's biggest mobile operator Econet Wireless said on Friday the government had ordered it to shut down its internet services until further notice following days of deadly protests over steep fuel price hikes.
The Zimbabwe Association of Doctors for Human Rights has said it had treated 68 cases of gunshot wounds and 100-plus other cases of "assaults with sharp objects, booted feet, baton sticks" and more. The security guard tells the AP a group of uniformed soldiers attacked him at work. Zimbabweans heeded a nationwide stay-at-home call earlier this week in protest.
Pastor Mawarire, who briefly appeared in court on Thursday 17 January 2019 returns to Harare Magistrates Court on Friday 18 January 2019 for continuation of court proceedings before Harare Magistrate Lucy Mungwari, who is expected to deliver a ruling on an application filed by the clergyman's lawyers challenging his placement on remand.
Mnangagwa is set to plead for more worldwide investment in Zimbabwe at the World Economic Forum in Davos, Switzerland.
As life returned to a semblance of normality in Harare, civilians ventured outside to stock up on food and other supplies while police continued to patrol the streets. Hanzi further said the personal security of people in the country had also been compromised as they were also unable to efficiently communicate using the popular social media platforms to alert each other of the security situations in their respective areas as well as sharing other issues of public interest and concern, such as the availability of essential services and products. Some said they can no longer afford fares for public transport, and some shops have run out of basics such as bread.